Technical Field
[0001] The present invention relates to a balloon catheter.
Background art
[0002] A balloon catheter is known that is used in treatments that dilate a constricted
location of a blood vessel. Patent Literature 1 discloses a balloon catheter that
is provided with a catheter tube, a balloon, three linear members, and a fixed cone-shaped
portion. The catheter tube (sometimes also referred to as a "catheter shaft") has
an inner tube and an outer tube. The balloon is joined to the outer tube and the inner
tube. The balloon inflates when a compressed fluid is supplied. The three linear members
are disposed on the outer peripheral side of the balloon. A distal end side of the
fixed cone-shaped portion is joined to a distal end of the inner tube. A proximal
end side of the fixed cone-shaped portion is joined to the three linear members. The
fixed cone-shaped portion is elastically deformable. The three linear members move
in a direction away from the inner tube in accordance with the inflation of the balloon.
The fixed cone-shaped portion extends in response to the movement of the three linear
members in the direction away from the inner tube. The fixed cone-shaped portion contracts
in accordance with the deflation of the balloon, and the three linear members move
in a direction approaching the inner tube.
Citation List
Patent Literature
Summary of Invention
[0004] In the case of the balloon catheter disclosed in Patent Literature 1, the fixed cone-shaped
portion joined to the distal end of the inner tube has an outer diameter that is sufficiently
larger than the inner tube even in a deflated state. Thus, from the point of view
of crossability, there is room for improvement.
US 2004/034384 A1 discloses a balloon catheter with a linear member straddling the inflatable region
of the balloon wherein the linear member includes a hard portion and a flexible portion
that is a portion other than the hard portion wherein radiopaque markers are respectively
provided in two positions separated from each other in the extending direction of
the catheter shaft.
[0005] An object of the present invention is to provide a balloon catheter having superior
crossability.
[0006] A balloon catheter of the present invention as defined by claim 1, comprises a balloon/shaft
assembly that includes a catheter shaft extending from a proximal end to a distal
end and a balloon connected to the catheter shaft, the balloon having an inflatable
region capable of inflating outward in a radial direction around the catheter shaft;
and a linear member straddling the inflatable region of the balloon and being mounted
on the balloon/shaft assembly at a distal end position located further toward the
distal end side than the inflatable region and at a proximal end position located
further toward the proximal end side than the inflatable region, and wherein the linear
member includes: a hard portion that includes at least an outer portion disposed on
an opposite side to an inner portion facing the inflatable region, of a portion disposed
along an outer peripheral surface of the inflatable region in an inflated state, and
a flexible portion that is a portion other than the hard portion, the flexible portion
being extendable and having a lower hardness than the hard portion. Preferred embodiments
are defined by the dependent claims.
[0007] In the above-described balloon catheter, when the balloon is inflated, the flexible
portion of the linear member extends. As a result, of the hard portion of the linear
member, the portion that is disposed along the outer peripheral surface of the inflatable
region of the balloon moves to the outside. The hardness of the hard portion is higher
than that of the flexible portion. Thus, when the balloon is inflated in a state in
which the balloon is disposed at a constricted portion of a blood vessel, the hard
portion acts appropriately on the constricted portion of the blood vessel.
[0008] As described above, the balloon catheter can cause the flexible portion to extend
in accordance with the inflation of the balloon, cause the portion of the hard portion
disposed along the outer peripheral surface of the inflatable region to move to the
outside, and cause the hard portion to act appropriately on the constricted portion
inside the blood vessel. As a result, in order to make the portion of the hard portion
disposed along the outer peripheral surface of the inflatable region movable to the
outside, the balloon catheter does not require a member other than the linear member.
Thus, when a user tries to move the balloon as far as the constricted portion of the
blood vessel, the balloon catheter can inhibit a member other than the linear member
from obstructing the movement of the balloon. In this way, the balloon catheter can
cause the balloon to appropriately approach and be disposed at the constricted portion
of the blood vessel.
[0009] With respect to the present invention, the flexible portion may extend between the
distal end position and the proximal end position, and the hard portion may protrude
to the outside from a portion of the flexible portion that is disposed along the outer
peripheral surface of the inflatable region in the inflated state. In this case, the
balloon catheter can suppress the hard portion from obstructing the extending of the
portions of the flexible portion apart from the portion from which the hard portion
protrudes. As a result, the flexible portion extends appropriately at the portions
apart from the portion of the flexible portion from which the hard portion protrudes.
Thus, as a result of the flexible portion extending appropriately, the balloon catheter
can easily cause the hard portion to move to the outside in accordance with the inflation
of the balloon.
[0010] With respect to the present invention, a direction extending to the outside along
a distal end portion may be inclined toward the proximal end side, the distal end
portion being an end portion on the distal end side of the hard portion. In this case,
the balloon catheter can suppress the linear member from being caught on the inner
wall of the blood vessel, when the balloon catheter moves inside the blood vessel
in the course of the user causing the balloon to approach the constricted portion
of the blood vessel. Thus, the user can easily move the balloon as far as the constricted
portion of the blood vessel.
[0011] With respect to the present invention, a direction extending to the outside along
a proximal end portion may be inclined toward the distal end side, the proximal end
portion being an end portion on the proximal end side of the hard portion. In this
case, the balloon catheter can suppress the linear member from being caught on the
inner wall of the blood vessel, when the balloon catheter moves inside the blood vessel
in the course of the user pulling the balloon catheter out from the blood vessel.
Thus, the user can easily pull the balloon catheter out from the blood vessel.
[0012] With respect to the present invention, a first direction extending to the outside
along a distal end portion may be inclined toward the proximal end side, the distal
end portion being an end portion on the distal end side of the hard portion, a second
direction extending to the outside along a proximal end portion may be inclined toward
the distal end side, the proximal end portion being an end portion on the proximal
end side of the hard portion, and an angle of the first direction with respect to
an extending direction of the catheter shaft may be smaller than an angle of the second
direction with respect to the extending direction of the catheter shaft. In this case,
the balloon catheter can suppress the linear member from being caught on the inner
wall of the blood vessel, when the balloon catheter moves inside the blood vessel
in the course of the user causing the balloon to approach the constricted portion
of the blood vessel. Thus, the user can easily move the balloon as far as the constricted
portion of the blood vessel. Further, the balloon catheter can suppress the linear
member from being caught on the inner wall of the blood vessel, when the balloon catheter
moves inside the blood vessel in the course of the user pulling the balloon catheter
out from the blood vessel. Thus, the user can easily pull the balloon catheter out
from the blood vessel.
[0013] With respect to the present invention, a slit may be formed extending toward the
inside in the radial direction from an end portion on the outside of the hard portion.
In this case, when the flexible portion tries to extend when the balloon is inflated,
due to the slit, the linear member can suppress the extending of the flexible portion
from being obstructed by the hard portion. As a result, the linear member extends
appropriately in accordance with the inflation of the balloon, and can follow the
inflation of the balloon. Thus, the balloon catheter can inhibit the linear member
from breaking away from the balloon when the balloon is inflated, or inhibit the linear
member from obstructing the inflation of the balloon.
[0014] With respect to the present invention, a bottom portion may be positioned further
to the inside, in the radial direction, than a boundary between the flexible portion
and the hard portion, the bottom portion being a portion furthermost to the inside
of the slit. In this case, the hard portion is divided in the extending direction.
Thus, the linear member can appropriately suppress the extending of the flexible portion
from being obstructed by the hard portion. As a result, the balloon catheter can more
appropriately inhibit the linear member from breaking away from the balloon when the
balloon is inflated.
[0015] With respect to the present invention, a bottom portion may be positioned, in the
radial direction, substantially in the same position as a boundary between the flexible
portion and the hard portion, the bottom portion being a portion furthermost to the
inside of the slit. In this case, the hard portion is divided in the extending direction.
Thus, the linear member can appropriately suppress the extending of the flexible portion
from being obstructed by the hard portion. As a result, the balloon catheter can more
appropriately inhibit the linear member from breaking away from the balloon when the
balloon is inflated. Further, since the slit is not formed in the flexible portion,
the flexible portion can maintain strength when extending.
[0016] With respect to the present invention, a bottom portion may be positioned further
to the outside, in the radial direction, than a boundary between the flexible portion
and the hard portion, the bottom portion being a portion furthermost to the inside
of the slit. In this case, by suppressing a depth of the slit to a minimum, the linear
member can significantly increase an area of the hard portion acting on the blood
vessel when the balloon is inflated. Thus, the balloon catheter can cause the hard
portion to act on the blood vessel even more appropriately when the balloon is inflated.
[0017] With respect to the present invention, the slit may be a notch where a part of the
linear member is cut out. In this case, the linear member can easily bend in a direction
orthogonal to the extending direction at a notched section. Thus, when the balloon
bends in the direction orthogonal to the extending direction, the balloon catheter
can cause the linear member to follow the balloon, and to bend. As a result, the balloon
catheter can inhibit the linear member from breaking away from the balloon when the
balloon bends.
[0018] With respect to the present invention, the slit may be an incision having two surfaces
that face each other and are in contact with each other. In this case, in comparison
to when the slit is a notch, an area of the portion on the outside of the linear member
can be increased. As a result, when the balloon is inflated, the area over which the
linear member is in contact with the blood vessel wall can be increased, compared
to when the slit is a notch. By increasing the area over which the linear member is
in contact with the blood vessel wall, the balloon catheter can cause the hard portion
to act on the blood vessel even more appropriately when the balloon is inflated.
[0019] With respect to the present invention, at least a part of the flexible portion of
the linear member may be bonded to the balloon. In this case, the linear member can
be held in a fixed position with respect to the balloon. Thus, the balloon catheter
can cause the linear member to act on the blood vessel when the balloon is inflated,
in a state in which the linear member is held in the correct position with respect
to the balloon.
[0020] With respect to the present invention, the linear member may be disposed along an
outer peripheral surface of the balloon in the inflated state. In this case, the movement
of the linear member with respect to the balloon can be suppressed.
[0021] With respect to the present invention, of the flexible portion, a thickness of a
portion located further toward the distal end side than the hard portion may be narrower
than a thickness of a portion located further toward the proximal end side than the
hard portion. In this case, in comparison to a case in which, of the flexible portion,
a thickness of the portion located further toward the distal end side than the hard
portion is larger than or equal to the thickness of the portion located further toward
the proximal end side than the hard portion, a diameter on the distal end side of
the balloon catheter can be reduced. As a result, the user can move the distal end
portion of the balloon catheter to the constricted portion inside the blood vessel
using less force.
[0022] With respect to the present invention, radiopaque markers are respectively provided
in two positions separated from each other in an extending direction of the catheter
shaft, of the two markers, the position of the marker provided on the distal end side
corresponds to a position of a boundary of the inflatable region on the distal end
side, in the extending direction of the catheter shaft, and of the two markers, the
position of the marker provided on the proximal end side corresponds to a position
of a boundary of the inflatable region on the proximal end side, in the extending
direction of the catheter shaft. In this case, the user can correctly identify the
inflatable region when the balloon is inflated, using the two markers. Further, the
hard portion is disposed corresponding to the inflatable region identified by the
two markers. Thus, the user can easily verify that he/she is causing the hard portion
of the linear member to act appropriately on the blood vessel at the inflatable region
identified by the two markers.
[0023] With respect to the present invention, the balloon may include a proximal end side
leg portion bonded to the catheter shaft at a position further toward the distal end
side than the proximal end position, and an end portion on the proximal end side of
the linear member may be bonded to the balloon/shaft assembly at the proximal end
position. In this case, the linear member can be separated from the proximal end side
of the balloon.
[0024] With respect to the present invention, the balloon may include a proximal end side
leg portion bonded to the catheter shaft at the proximal end position, and an end
portion on the proximal end side of the linear member may be bonded to an outer peripheral
surface of the proximal end side leg portion. In this case, since the linear member
is bonded to the balloon, the linear member can be easily bonded to the catheter shaft.
[0025] With respect to the present invention, the linear member may be formed of a synthetic
resin. In this case, the linear member can be easily manufactured.
[0026] With respect to the present invention, of both end portions in an extending direction
of the linear member, at least one end portion may be connected to the catheter shaft.
In this case, the balloon catheter in which the linear member is disposed along the
outer peripheral surface of the balloon when the balloon is inflated can be easily
manufactured.
Brief description of the drawings
[0027]
Fig. 1 is a side view of a balloon catheter 10 according to a first embodiment.
Fig. 2 is a side view of a balloon 3 and a linear member 4 in a deflated state.
Fig. 3 is a cross-sectional view in the direction of arrows along a line I - I shown
in Fig. 2.
Fig. 4 is a cross-sectional view of the balloon 3 and the linear member 4 in the deflated
state.
Fig. 5 is a side view of the balloon 3 and the linear member 4 in an inflated state.
Fig. 6 is a cross-sectional view in the direction of arrows along a line II - II shown
in Fig. 5.
Fig. 7 is a cross-sectional view of the balloon 3 and the linear member 4 in the inflated
state.
Fig. 8 shows a side view and cross-sectional views of the linear member 4.
Fig. 9 is a cross-sectional view of the balloon 3 and the linear member 4 according
to a second embodiment.
Fig. 10 is a cross-sectional view of the balloon 3 and a linear member 6 according
to a third embodiment.
Fig. 11 shows a side view and cross-sectional views of the linear member 6.
Fig. 12 is a cross-sectional view of the balloon 3 and a linear member 7 according
to a fourth embodiment.
Fig. 13 shows a side view and cross-sectional views of the linear member 7.
Fig. 14 is a cross-sectional view of the balloon 3 and a linear member 8 according
to a fifth embodiment.
Fig. 15 shows a side view and cross-sectional views of the linear member 8.
Fig. 16 is a side view of the balloon 3 and a linear member 9 according to a sixth
embodiment.
Fig. 17 is a cross-sectional view in the direction of arrows along a line III - III
shown in Fig. 16.
Fig. 18 is a cross-sectional view of the balloon 3 and the linear member 9 in the
inflated state.
Fig. 19 shows a side view and cross-sectional views of the linear member 9.
Fig. 20 is a cross-sectional view of an expanded part of the linear member 9 according
to a seventh embodiment.
Fig. 21 is a cross-sectional view of an expanded part of the linear member 9 according
to an eighth embodiment.
Fig. 22 is a cross-sectional view of an expanded part of the linear member 9 according
to a ninth embodiment.
Description of Embodiments
First embodiment
[0028] Hereinafter, a balloon catheter 10 according to a first embodiment of the present
invention will be explained with reference to Fig. 1 to Fig. 8. As shown in Fig. 1,
the balloon catheter 10 has a catheter shaft 2, a balloon 3, and linear members 4A,
4B, and 4 C (refer to Fig. 3, hereinafter collectively referred to as "linear members
4"). Hereinafter, the catheter shaft 2 and the balloon 3 are collectively referred
to as a "balloon/shaft assembly 25." The balloon 3 is connected to an end portion
on one side of the catheter shaft 2. The linear members 4 are disposed on the outside
of the balloon 3 in an inflated state. The balloon catheter 10 is used in a state
in which a hub 5 is connected to an end portion on the other side of the catheter
shaft 2. The hub 5 can supply compressed fluid to the balloon 3 via the catheter shaft
2. Hereinafter, the one end (of both ends) of the catheter shaft 2 on the one side
is referred to as a "distal end." The other end (of both ends) of the catheter shaft
2 is referred to as a "proximal end." A direction extending along the catheter shaft
2 is referred to as an "extending direction." In a plane orthogonal to the extending
direction, of a radial direction taking a center of a cross section of the catheter
shaft 2 as a reference, a side closer to the center of the cross section of the catheter
shaft 2 is referred to as an "inner side" and a side further away from the center
of the cross section of the catheter shaft 2 is referred to as an "outer side."
Catheter shaft 2
[0029] As shown in Fig. 4 and Fig. 7, the catheter shaft 2 has an outer tube 21 and an inner
tube 22. The outer tube 21 and the inner tube 22 are both flexible tubular members.
The outer tube 21 has a lumen 213, which is a space surrounded by an inner surface
212, which is a surface on the inner side of the outer tube 21. The inner tube 22
has a lumen 223, which is a space surrounded by an inner surface 222, which is a surface
on the inner side of the inner tube 22. The outer tube 21 and the inner tube 22 are
formed of a polyamide resin. The inner diameter of the outer tube 21 is larger than
the outer diameter of the inner tube 22.
[0030] Apart from a predetermined portion on the distal end side, the inner tube 22 is disposed
inside the lumen 213 of the outer tube 21. The predetermined portion on the distal
end side of the inner tube 22 protrudes toward the distal end side from an end (hereinafter
referred to as a "distal end 211") on the distal end side of the outer tube 21. The
end (hereinafter referred to as a "distal end 221") on the distal end side of the
inner tube 22 is disposed further toward the distal end side than the distal end 211
of the outer tube 21. Hereinafter, the predetermined portion on the distal end side
of the inner tube 22 is referred to as a "protruding portion 225." Radiopaque markers
(hereinafter simply referred to as "markers") 22A and 22B are fitted to the protruding
portion 225 of the inner tube 22. Resin into which a radiopaque material is mixed
is used as the material of the markers 22A and 22B. The markers 22A and 22B are fixed
to an outer surface 224, which is an outer peripheral surface of the inner tube 22,
as a result of cylindrical members formed of the above-described material being crimped
onto the protruding portion 225 of the inner tube 22. The markers 22A and 22B have
a predetermined length in the extending direction. The markers 22A and 22B do not
allow the passage of radiation. The marker 22A is disposed further toward the distal
end side than the marker 22B. The markers 22A and 22B are separated from each other
in the extending direction.
[0031] As shown in Fig. 2, Fig. 4, Fig. 5, and Fig. 7, of an outer surface 214, which is
the outer peripheral surface of the outer tube 21, a mounting member 21A is mounted
on a portion further toward the proximal end side than the distal end 211. The mounting
member 21A is a cylindrical member that can move along the extending direction. The
inner diameter of the mounting member 21A is larger than the outer diameter of the
outer tube 21. A thermoplastic resin, such as a polyamide resin or the like, is used
as the material of the mounting member 21A.
[0032] As shown in Fig. 4 and Fig. 7, the compressed fluid supplied from the hub 5 (refer
to Fig. 1) flows through a space of the lumen 213 of the outer tube 21 other than
the lumen 223 of the inner tube 22. The balloon 3 inflates (refer to Fig. 5 to Fig.
7) in accordance with the supply of the compressed fluid. A guide wire that is not
shown in the drawings is inserted through the lumen 223 of the inner tube 22
[0033] The material of the outer tube 21 and the inner tube 22 is not limited to the polyamide
resin, and can be changed to another flexible material. For example, a synthetic resin
material, such as a polyethylene resin, a polypropylene resin, a polyurethane resin,
a polyimide resin and the like, may be used as the material of the outer tube 21 and
the inner tube 22. Additives may be mixed with the synthetic resin material. Different
synthetic resin materials may be used as the materials of the outer tube 21 and the
inner tube 22, respectively. The material of the markers 22A and 22B is not limited
to the resin into which the radiopaque material is mixed, and can be changed to another
material that does not allow the passage of radiation. For example, a resin on which
a radiopaque material is deposited, or a material such as metal or the like that does
not allow the passage of radiation may be used as the material of the markers 22A
and 22B.
Balloon 3
[0034] As shown in Fig. 2 to Fig. 4, the balloon 3 deflates to the inner side when the compressed
fluid is not supplied. As shown in Fig. 5 to Fig. 7, the balloon 3 inflates to the
outer side when the compressed fluid is supplied. The balloon 3 is formed of a polyamide
resin. As shown in Fig. 2, Fig. 4, Fig. 5, and Fig. 7, the balloon 3 includes a proximal
end side leg portion 31, a proximal end side cone region 32, an inflatable region
33, a distal end side cone region 34, and a distal end side leg portion 35. The proximal
end side leg portion 31, the proximal end side cone region 32, the inflatable region
33, the distal end side cone region 34, and the distal end side leg portion 35 respectively
correspond to portions of the balloon 3 divided into five in the extending direction.
The length of the inflatable region 33 in the extending direction is longer than the
respective lengths in the extending direction of the proximal end side leg portion
31, the proximal end side cone region 32, the distal end side cone region 34, and
the distal end side leg portion 35.
[0035] As shown in Fig. 4 and Fig. 7, the proximal end side leg portion 31 is connected,
by thermal welding, to the outer surface 214 that is the outer peripheral surface
of the outer tube 21, at a portion located further toward the proximal end side than
the distal end 211 and further toward the distal end side than the portion on which
the mounting member 21A is mounted. The proximal end side cone region 32 is adjacent
to the distal end side of the proximal end side leg portion 31. The inflatable region
33 is adjacent to the distal end side of the proximal end side cone region 32. The
distal end side cone region 34 is adjacent to the distal end side of the inflatable
region 33. The distal end side leg portion 35 is adjacent to the distal end side of
the distal end side cone region 34. The distal end side leg portion 35 is connected,
by thermal welding, to the outer surface 224 of the protruding portion 225 of the
inner tube 22, at a portion located further toward the proximal end side than the
distal end 221. The proximal end side leg portion 31, the proximal end side cone region
32, the inflatable region 33, the distal end side cone region 34, and the distal end
side leg portion 35 are disposed side by side in that order from the proximal end
side toward the distal end side. The proximal end side cone region 32, the inflatable
region 33, the distal end side cone region 34, and the distal end side leg portion
35 cover the protruding portion 225 of the inner tube 22 from outside.
[0036] As shown in Fig. 2 to Fig. 4, three pleats are formed by the balloon 3 in the deflated
state. The balloon 3 is a three pleat type balloon. As shown in Fig. 3, in the deflated
state, the balloon 3 is folded over so as to form three pleats 3A, 3B, and 3C. Each
of the pleats 3A, 3B, and 3C is wrapped around the protruding portion 225 of the inner
tube 22. In this state, the pleat 3A covers the linear member 4A, which will be described
later, from outside. The pleat 3B covers the linear member 4B, which will be described
later, from outside. The pleat 3C covers the linear member 4C, which will be described
later, from outside. The pleats 3A, 3B, and 3C are also called "flaps" and "wings."
[0037] The inflated state of the balloon 3 will be explained with reference to Fig. 5 to
Fig. 7. As shown in Fig. 6, the cross-sectional shape of the balloon 3 is circular.
As shown in Fig. 5 and Fig. 7, the proximal end side cone region 32 has a tapered
shape. The diameter of the proximal end side cone region 32 increases continuously
and linearly from the proximal end side toward the distal end side. The diameter of
the inflatable region 33 is the same across the whole length in the extending direction.
The distal end side cone region 34 has a tapered shape. The diameter of the distal
end side cone region 34 decreases continuously and linearly from the proximal end
side toward the distal end side. The diameter of the cross section of the balloon
3 changes in a stepped manner between the proximal end side cone region 32, the inflatable
region 33, and the distal end side cone region 34. The inflatable region 33 is a portion
of the balloon 3 having the maximum diameter.
[0038] As shown in Fig. 7, a boundary of the inflatable region 33 on the distal end side
is aligned, in the extending direction, with a position P11 of an end portion on the
distal end side of the marker 22A. In other words, the boundary of the inflatable
region 33 on the distal end side is a position of a boundary between the inflatable
region 33 and the distal end side cone region 34. A boundary of the inflatable region
33 on the proximal end side is aligned, in the extending direction, with a position
P21 of an end portion on the proximal end side of the marker 22B. In other words,
the boundary of the inflatable region 33 on the proximal end side is a position of
a boundary between the inflatable region 33 and the proximal end side cone region
32.
[0039] The material of the balloon 3 is not limited to the polyamide resin, and can be changed
to another flexible material. For example, a polyethylene resin, a polypropylene resin,
a polyurethane resin, a polyimide resin, silicone rubber, natural rubber, and the
like may be used as the material of the balloon 3. In the above description, the method
of connecting the outer tube 21 and the inner tube 22 to the balloon 3 is not limited
to the thermal welding. For example, each of the outer tube 21 and the inner tube
22 may be connected using an adhesive.
Linear member 4
[0040] The linear member 4 will be explained with reference to Fig. 4 to Fig. 8. The linear
member 4 has a restoring force with respect to bending deformation. The linear member
4 is a monofilament-shaped elastic body. The linear members 4A, 4B, and 4C have the
same shape. The linear member 4 extends along the extending direction.
[0041] As shown in Fig. 4, Fig. 5, and Fig. 7, an end portion on the distal end side of
the linear member 4 is connected, by thermal welding, to a portion of the outer peripheral
surface of the distal end side leg portion 35 of the balloon 3 that is further to
the distal end side than the center in the extending direction. Hereinafter, a position
at which the end portion on the distal end side of the linear member 4 is connected,
in the extending direction of the balloon catheter 10, is referred to as a "distal
end position M1." In the extending direction, the distal end position M1 is disposed
further toward the distal end side than the inflatable region 33 of the balloon 3
in the inflated state. The distal end position M1 corresponds to a position further
toward the distal end side than the center, in the extending direction, of the distal
end side leg portion 35 of the balloon 3. The end portions on the distal end side
of each of the linear members 4A, 4B, and 4C are connected, respectively, to positions
that divide the outer peripheral surface of the distal end side leg portion 35 of
the balloon 3 into three equal parts in the circumferential direction.
[0042] An end portion on the proximal end side of the linear member 4 is connected, by thermal
welding, to a portion of the outer peripheral surface of the mounting member 21A located
further toward the proximal end side than the center in the extending direction. Hereinafter,
a position at which the end portion on the proximal end side of the linear member
4 is connected, in the extending direction of the balloon catheter 10, is referred
to as a "proximal end position M2." In the extending direction, the proximal end position
M2 is disposed further toward the proximal end side than the inflatable region 33
of the balloon 3 in the inflated state. The end portions on the proximal end side
of each of the linear members 4A, 4B, and 4C are connected, respectively, to positions
that divide the outer peripheral surface of the mounting member 21A into three equal
parts in the circumferential direction. The linear member 4 is connected at the distal
end position M1 and the proximal end position M2, and is not connected to the balloon
3 at other portions thereof.
[0043] The linear member 4 is disposed between the distal end position M1 and the proximal
end position M2 so as to straddle the inflatable region 33 of the balloon 3. As shown
in Fig. 6, when the balloon 3 is in the inflated state, the linear members 4A, 4B,
and 4C extend in straight lines in the extending direction, respectively, at positions
that divide the outer peripheral surface of the inflatable region 33 of the balloon
3 into three approximately equal parts in the circumferential direction.
[0044] As shown in Fig. 4, Fig. 5, and Fig. 7, the linear member 4 has a flexible portion
41, and a hard portion 42. The flexible portion 41 extends between the proximal end
position M2 and the distal end position M1. The flexible portion 41 includes a first
portion 411, a second portion 412, and a third portion 413. The first portion 411,
the second portion 412, and the third portion 413 respectively correspond to portions
of the flexible portion 41 that is divided into three in the extending direction.
An end portion on the proximal end side of the first portion 411 is connected to the
outer peripheral surface of the mounting member 21A, at the proximal end position
M2. The second portion 412 is adjacent to the distal end side of the first portion
411. The third portion 413 is adjacent to the distal end side of the second portion
412. An end portion on the distal end side of the third portion 413 is connected to
the outer peripheral surface of the distal end side leg portion 35 of the balloon
3, at the distal end position M1. The hard portion 42 is laminated on the second portion
412 of the flexible portion 41, at a portion on the opposite side to a portion facing
the balloon 3.
[0045] Fig. 8 shows cross sections of the linear member 4 at each of a line A1 - A1, a line
B1 - B1, and a line C1 - C1. The cross-sectional shape of the linear member 4 is a
trapezoid shape or a triangular shape. This is explained more specifically below.
[0046] The cross-sectional shape of the flexible portion 41 (the first portion 411 to the
third portion 413) is a trapezoid shape. Hereinafter, of the first portion 411 of
the flexible portion 41, a portion facing the balloon 3 in the inflated state (refer
to Fig. 6) is referred to as an "inner portion 411A." Of the first portion 411, a
portion on the opposite side to the inner portion 411A is referred to as an "outer
portion 411B." Of the second portion 412 of the flexible portion 41, a portion facing
the balloon 3 in the inflated state is referred to as an "inner portion 412A." Of
the first portion 412, a portion on the opposite side to the inner portion 412A is
referred to as an "outer portion 412B." Of the third portion 413 of the flexible portion
41, a portion facing the balloon 3 is referred to as an "inner portion 413A." Of the
third portion 413, a portion on the opposite side to the inner portion 413A is referred
to as an "outer portion 413B." The inner portions 411A, 412A, and 413A and the outer
portions 411B, 412B, and 413B respectively correspond to a lower base and an upper
base of the trapezoid that is the cross-sectional shape.
[0047] A length between the inner portion 413A and the outer portion 413B of the third portion
413, namely, a thickness R13 of a portion of the flexible portion 41 located further
toward the distal end side than the hard portion 42, is 0.15 mm. A length between
the inner portion 411A and the outer portion 411B of the first portion 411, namely,
a thickness R11 of a portion of the flexible portion 41 located further toward the
proximal end side than the hard portion 42, is 0.23 mm. The thickness R13 is narrower
than the thickness R11.
[0048] The shape of the cross section of the hard portion 42 is an equilateral triangle
shape having the outer portion 412B of the second portion 412 as one side. The hard
portion 42 protrudes to the outside from the outer portion 412B of the second portion
412 of the flexible portion 41. Hereinafter, an end portion on the outside of the
hard portion 42 is referred to as an "outer portion 42B." The outer portion 42B corresponds
to an apex of the equilateral triangle shape. The outer portion 42B is peaked. A length
between the inner portion 412A and the outer portion 42B, namely a thickness R12 of
the portion at which the second portion 412 of the flexible portion 41 and the hard
portion 42 are laminated, is 0.4 mm.
[0049] An end surface on the distal end side of the hard portion 42 is referred to as a
"distal end surface 42S." A virtual first direction D11 is defined that extends toward
the outside along the distal end surface 42S of the hard portion 42. The first direction
D11 is inclined toward the proximal end side with respect to a direction orthogonal
to the extending direction. An end surface on the proximal end side of the hard portion
42 is referred to as a "proximal end surface 42K." A virtual second direction D12
is defined that extends toward the outside along the proximal end surface 42K of the
hard portion 42. The second direction D12 is inclined toward the distal end side with
respect to the direction orthogonal to the extending direction. An acute angle, of
angles formed between the first direction D11 and the extending direction, is defined
as a first angle θ11. The first angle θ11 is an angle between 4 to 13 degrees, for
example. The first angle θ11 is preferably 5 degrees. An acute angle, of angles formed
between the second direction D12 and the extending direction, is defined as a second
angle θ12. The second angle θ12 is an angle between 5 to 16 degrees, for example.
The second angle θ12 is preferably 16 degrees. The preferable five degrees of the
first angle θ11 is smaller than the preferable sixteen degrees of the second angle
θ12.
[0050] As shown in Fig 7, when the balloon 3 is in the inflated state, a position of a boundary
on the distal end side of the second portion 412 of the flexible portion 41, namely,
a position of a boundary between the second portion 412 and the third portion 413,
is aligned, in the extending direction, with the position P11 of the end portion on
the distal end side of the marker 22A. A position of a boundary on the proximal end
side of the second portion 412 of the flexible portion 41, namely, a position of a
boundary between the first portion 411 and the second portion 412, is aligned, in
the extending direction, with the position P21 of the end portion on the proximal
end side of the marker 22B.
[0051] As described above, the boundary on the distal end side of the inflatable region
33 is aligned, in the extending direction, with the position P11 of the end portion
on the distal end side of the marker 22A. The boundary on the proximal end side of
the inflatable region 33 is aligned, in the extending direction, with the position
P21 of the end portion on the proximal end side of the marker 22B. Thus, when the
balloon 3 is in the inflated state, the inflatable region 33 of the balloon 3, the
second portion 412 of the flexible portion 41, and the hard portion 42 are all disposed
in the same position in the extending direction. The second portion 412 of the flexible
portion 41 is disposed along the outer peripheral surface of the inflatable region
33 of the balloon 3. The inner portion 412A of the second portion 412 of the flexible
portion 41 faces the inflatable region 33 of the balloon 3. The hard portion 42 is
disposed on the opposite side to the portion facing the inflatable region 33 of the
balloon 3, namely, on the opposite side to the inner portion 412A of the second portion
412 of the flexible portion 41.
[0052] The linear member 4 is formed of a polyamide resin. More specifically, the flexible
portion 41 is formed of a polyamide elastomer. The hardness of the flexible portion
41 is a value within a range of D25 to D63 as prescribed in ISO 868. The hard portion
42 is formed of a polyamide resin. The hardness of the hard portion 42 is a value
within a range of D70 to D95 as prescribed in ISO 868. The flexible portion 41 is
softer than the hard portion 42. In comparison to the hard portion 42, the flexible
portion 41 has excellent extendability.
[0053] A state of the linear member 4 when the balloon 3 inflates as a result of the compressed
fluid being supplied from the hub 5 will be explained. In accordance with the inflation
of the balloon 3, the hard portion 42 of the linear member 4 separates from the protruding
portion 225 of the inner tube 22 (refer to Fig. 7). At that time, of the flexible
portion 41 of the linear member 4, the first portion 411 and the third portion 413
elastically deform so as to extend along the extending direction, while the second
portion 412 on which the hard portion 42 is laminated does not. As a result, the hard
portion 42 easily separates from the protruding portion 225 of the inner tube 22.
The inner surface 412A of the second portion 412 of the flexible portion 41 is disposed
along the outer peripheral surface of the inflatable region 33 of the balloon 3. The
outer portion 42B (refer to Fig. 8) of the hard portion 42 protrudes to the outside
from the outer portion 412B of the second portion 412 of the flexible portion 41 (refer
to Fig. 6). As described above, in comparison to the flexible portion 41, the hard
portion 42 does not easily extend. Thus, even when the balloon 3 inflates, the second
portion 412 of the flexible portion 41 of the linear member 4 does not extend to the
same extent as the first portion 411 and the third portion 413 of the flexible portion
41.
[0054] A state of the linear member 4 when the balloon 3 deflates as a result of the compressed
fluid being discharged from the balloon 3 in the inflated state will be explained.
When the balloon 3 is deflated, the first portion 411 and the third portion 413 of
the flexible portion 41 of the linear member 4 that have extended in the extending
direction contract due to the restoring force. The hard portion 42 of the linear member
4 approaches the protruding portion 225 of the inner tube 22 (refer to Fig. 4). Warping
of the linear member 4 is suppressed by the contraction of the first portion 411 and
the third portion 413 of the flexible portion 41. The linear member 4A is covered
from the outside by the pleat 3A. The linear member 4B is covered from the outside
by the pleat 3B. The linear member 4C is covered from the outside by the pleat 3C
(refer to Fig. 3).
[0055] As long as the flexible portion 41 and the hard portion 42 of the linear member 4
have favorable hardness and extendability, the material thereof is not limited to
the polyamide resin, and another synthetic resin can be used. The material is not
limited to the synthetic resin, and stainless steel, an Ni-Ti alloy, or carbon fiber
may be used.
Main operations and effects of first embodiment
[0056] In the balloon catheter 10 of the first embodiment, when the balloon 3 inflates,
since the inflatable region 33 moves to the outside, the hard portion 42 of the linear
member 4 that is disposed along the outer peripheral surface of the inflatable region
33 also tries to move to the outside. In response to this, of the flexible portion
41 of the linear member 4, the first portion 411 and the third portion 413 on which
the hard portion 42 is not laminated elastically deform so as to extend along the
extending direction. As a result, the hard portion 42 can easily move to the outside.
The outer portion 42B of the hard portion 42 of the linear member 4 protrudes to the
outside from the outer portion 412B on the opposite side to the inner portion 412A
that faces the outer peripheral surface of the balloon 3. The hard portion 42 has
a higher hardness than the flexible portion 41. Thus, in a state in which the balloon
3 is disposed in a constricted portion of a blood vessel, when the balloon 3 is inflated,
the hard portion 42 acts appropriately on the constricted portion of the blood vessel.
For example, the hard portion 42 is peaked at the outer portion 42B, and thus the
hard portion 42 can easily bite into a lesioned part (not shown in the drawings) of
the blood vessel. As a result, in a state in which the linear member 4 causes the
balloon 3 to be in a state of not easily slipping with respect to the lesioned part
of the blood vessel, the lesioned part can be expanded from the inside by the inflation
of the balloon 3.
[0057] In the balloon catheter 10, the first portion 411 and the third portion 413 of the
flexible portion 41 are caused to extend in accordance with the inflation of the balloon
3, and the hard portion 42 is caused to move to the outside. In this way, the balloon
catheter 10 can cause the hard portion 42 to act on the constricted portion inside
the blood vessel. As a result, other than the linear members 4, the balloon catheter
10 does not require a member that is necessary to be able to move the hard portion
42 to the outside. Thus, when a user tries to move the balloon 3 as far as the constricted
portion of the blood vessel, the balloon catheter 10 can inhibit obstruction of the
movement of the balloon 3 by the member other than the linear members 4. In this way,
the balloon catheter 10 can cause the balloon 3 to appropriately approach and be disposed
at the constricted portion of the blood vessel.
[0058] The flexible portion 41 of the linear member 4 extends between the distal end position
M1 and the proximal end position M2. Of the flexible portion 41, the hard portion
42 is laminated on the second portion 412 that is disposed along the outer peripheral
surface of the inflatable region 33 in the inflated state. When the balloon 3 is in
the inflated state, the hard portion 42 protrudes to the outside from the outer portion
412B of the second portion 412 of the flexible portion 41. Thus, the balloon catheter
10 can inhibit the hard portion 42 from obstructing the extending of the first portion
411 and the third portion 413 of the flexible portion 41, on which the hard portion
42 is not laminated. The flexible portion 41 extends appropriately at the first portion
411 and the third portion 413. Thus, the balloon catheter 10 can easily move the hard
portion 42 to the outside in accordance with the inflation of the balloon 3.
[0059] The first direction D11, which extends to the outside along the distal end surface
42S that is the end portion of the hard portion 42 on the distal end side, is inclined
toward the proximal end side. In this case, when the balloon catheter 10 moves inside
the blood vessel in the course of the user causing the balloon 3 to approach the constricted
portion of the blood vessel, the linear member 4 can be inhibited from catching on
the inner wall of the blood vessel. Thus, the user can smoothly move the balloon 3
as far as the constricted portion of the blood vessel. Further, the second direction
D12, which extends to the outside along the proximal end surface 42K that is the end
portion of the hard portion 42 on the proximal end side, is inclined toward the distal
end side. In this case, when the balloon catheter 10 moves inside the blood vessel
in the course of the user pulling the balloon catheter 10 out from the blood vessel,
the linear member 4 can be inhibited from catching on the inner wall of the blood
vessel. Thus, the user can easily pull the balloon catheter 10 out from the blood
vessel.
[0060] With respect to the flexible portion 41, the thickness R13 of the third portion 413
located further toward the distal end side than the hard portion 42 is narrower than
the thickness R11 of the first portion 411 located further toward the proximal end
side than the hard portion 42. In this case, in comparison to a case in which the
thickness R13 is thicker than the thickness R11, or a case in which the thicknesses
R11 and R13 are the same as each other, the balloon catheter 10 can make the diameter
of the distal end portion smaller. Thus, the user can cause the balloon 3 of the balloon
catheter 10 to move as far as the constricted portion of the blood vessel using less
force.
[0061] The first angle θ11, which is the acute angle of the angles formed between the extending
direction and the first direction D11, is smaller than the second angle θ12, which
is the acute angle of the angles formed between the extending direction and the second
direction D12. In this case, the balloon catheter 10 can use the portion of the distal
end surface 42S to reduce a rate of change of the hardness in the extending direction
of the linear member 4. Further, since the first angle θ11 is small, the balloon catheter
10 can inhibit the linear members 4 from catching on the inner wall of the blood vessel
when the user moves the balloon catheter 10 as far as the constricted portion inside
the blood vessel. In this way, the user can easily move the balloon 3 as far as the
constricted portion of the blood vessel.
[0062] The protruding portion 225 of the inner tube 22 is provided with the markers 22A
and 22B in the positions separated from each other in the extending direction. The
position P11 of the distal end side of the distal end side marker 22A is aligned with
the position of the boundary of the distal end side of the inflatable region 33. The
position P21 of the proximal end side of the proximal end side marker 22B is aligned
with the position of the boundary of the proximal end side of the inflatable region
33. In this case, the user can correctly determine the inflatable region 33 when the
balloon 3 is inflated, using the markers 22A and 22B. Further, the hard portion 42
is disposed so as to correspond to the inflatable region 33 identified by the markers
22A and 22B. Thus, the user can easily ascertain that the hard portion 42 of the linear
member 4 is acting appropriately on the blood vessel at the inflatable region 33 identified
by the markers 22A and 22B.
[0063] The proximal end side leg portion 31 of the balloon 3 is connected to the outer tube
21 further toward the distal end side than the proximal end position M2. The proximal
end position M2 corresponds to the position at which the end portion on the proximal
end side of the linear member 4 is connected to the outer tube 21 via the mounting
member 21A. Thus, the balloon catheter 10 can cause the linear member 4 to be separated
from the end portion on the proximal end side of the balloon 3. In this case, the
end portion on the proximal end side of the linear member 4 is strongly fixed to the
outer tube 21. Further, the balloon catheter 10 can suppress an impact on the proximal
end side leg portion 31 of the balloon 3 caused by tension acting on the linear member
4.
[0064] The linear member 4 is formed of the synthetic resin. In this case, the linear member
4 that includes the flexible portion 41 and the hard portion 42 can easily be manufactured
by injection molding, extrusion molding or the like.
Second embodiment
[0065] A balloon catheter 20 according to a second embodiment of the present invention will
be explained with reference to Fig. 9. Points in which the second embodiment differs
from the first embodiment are as follows:
- The mounting member 21A (refer to Fig. 2 and the like) is not mounted on the outer
tube 21, and
- The end portion on the proximal end side of the linear member 4 is connected further
toward the proximal end side than the center in the extending direction of the proximal
end side leg portion 31 of the balloon 3.
[0066] Hereinafter, where the configuration is the same as that of the first embodiment,
the same reference numerals are assigned and an explanation thereof is omitted.
[0067] As shown in Fig. 9, the end portion on the proximal end side of the linear member
4 is connected, by thermal welding, further toward the proximal end side than the
center in the extending direction of the outer peripheral surface of the proximal
end side leg portion 31 of the balloon 3. The proximal end position M2 that shows
the position at which the end portion on the proximal end side of the linear member
4 is connected corresponds to a position, of the proximal end side leg portion 31
of the balloon 3, that is located further toward the proximal end side than the center
in the extending direction.
Main operations and effects of second embodiment
[0068] In the balloon catheter 20 according to the second embodiment, the linear member
4 can be fixed to the outer tube 21 without needing the mounting member 21A. Thus,
the costs of the balloon catheter 10 can be reduced. Further, in comparison to a case
in which the linear member 4 is connected directly to the outer tube 21, the linear
member 4 can be reliably connected to the outer tube 21 by connecting the linear member
4 to the outer tube 21 via the balloon 3.
Third embodiment
[0069] A balloon catheter 30 according to a third embodiment of the present invention will
be explained with reference to Fig. 10 and Fig. 11. A point in which the third embodiment
differs from the second embodiment is that a linear member 6 is provided in place
of the linear member 4. Hereinafter, where the configuration is the same as that of
the first embodiment and the second embodiment, the same reference numerals are assigned
and an explanation thereof is omitted.
[0070] As shown in Fig. 10, the linear member 6 includes a flexible portion 61, and a hard
portion 62. The end portion on the proximal end side of the flexible portion 61 is
connected to the outer peripheral surface of the proximal end side leg portion 31
of the balloon 3, at the proximal end position M2. The hard portion 62 includes a
first portion 621 and a second portion 622. The first portion 621 is adjacent to the
distal end side of the flexible portion 61. The second portion 622 is adjacent to
the distal end side of the first portion 621. The end portion on the distal end side
of the second portion 622 is connected to the outer peripheral surface of the distal
end side leg portion 35 of the balloon 3, at the distal end position M1. The flexible
portion 61, the first portion 621 of the hard portion 62, and the second portion 622
of the hard portion 62 are disposed side by side in that order from the proximal end
toward the distal end along the extending direction.
[0071] The flexible portion 61 corresponds to the first portion 411 (refer to Fig. 8) of
the flexible portion 41 according to the first embodiment. The first portion 621 of
the hard portion 62 corresponds to the laminated portion (refer to Fig. 8) according
to the first embodiment, in which the second portion 412 of the flexible portion 41
and the hard portion 42 are laminated. The second portion 622 of the hard portion
62 corresponds to the third portion 413 (refer to Fig. 8) of the flexible portion
41 according to the first embodiment. The shape of each of the portions is the same.
The material of the flexible portion 61 is the same as the material of the flexible
portion 41 according to the first embodiment. The material of the hard portion 62
is the same as the material of the hard portion 42 according to the first embodiment.
[0072] Fig. 11 shows cross sections of the linear member 6 at each of a line A2 - A2, a
line B2 - B2, and a line C2 - C2. The shape of the cross section of the flexible portion
61 is a trapezoid shape. An inner portion 61A and an outer portion 61B respectively
correspond to the inner portion 411A and the outer portion 411B (refer to Fig. 8)
of the flexible portion 41. A length between the inner portion 61A and the outer portion
61B of the flexible portion 61, namely, a thickness R21 of the flexible portion 61,
is the same as the thickness R11 in the linear member 4. The shape of the cross section
of the first portion 621 of the hard portion 62 is an equilateral triangle shape.
An inner portion 621A and an outer portion 621B respectively correspond to the inner
portion 412A and the outer portion 42B (refer to Fig. 8) of the flexible portion 41.
A length between the inner portion 621A and the outer portion 621B, namely, a thickness
R22 of the first portion 621 of the hard portion 62, is the same as the thickness
R12 in the linear member 4. The shape of the cross section of the second portion 622
of the hard portion 62 is a trapezoid shape. An inner portion 622A and an outer portion
622B respectively correspond to the inner portion 413A and the outer portion 413B
(refer to Fig. 8) of the flexible portion 41. A length between the inner portion 622A
and the outer portion 622B of the hard portion 62, namely, a thickness R23 of the
second portion 622, is the same as the thickness R13 in the linear member 4. A distal
end surface 62S and a proximal end surface 62K respectively correspond to the distal
end surface 42S and the proximal end surface 42K (refer to Fig. 8) of the hard portion
42. A first direction D21 and a second direction D22 respectively correspond to the
first direction D11 and the second direction D12 (refer to Fig. 8). A first angle
θ21 and a second angle θ22 respectively correspond to the first angle θ11 and the
second angle θ12 (refer to Fig. 8). The preferable five degrees of the first angle
θ21 is smaller than the preferable sixteen degrees of the second angle θ22.
[0073] In accordance with the inflation of the balloon 3, the first portion 621 of the hard
portion 62 of the linear member 6 tries to move away from the protruding portion 225
of the inner tube 22. At this time, the flexible portion 61 of the linear member 6
elastically deforms so as to extend along the extending direction. Thus, the first
portion 621 of the hard portion 62 easily separates from the protruding portion 225
of the inner tube 22. The outer portion 621B of the first portion 621 of the hard
portion 62 protrudes to the outside with respect to the balloon 3.
Main operations and effects of third embodiment
[0074] In the balloon catheter 30 according to the third embodiment, the first portion 621
of the hard portion 62 is disposed in a portion, of the linear member 6, that is aligned
with the position, in the extending direction, of the inflatable region 33 of the
balloon 3 in the inflated state. When the balloon 3 is inflated, the flexible portion
61 of the linear member 6 elastically deforms so as to extend along the extending
direction. In this way, the first portion 621 of the hard portion 62 moves away from
the protruding portion 225 of the inner tube 22. The outer portion 621B is disposed
on the opposite side to the inner portion 621A that faces the outer peripheral surface
of the balloon 3. Thus, with the balloon catheter 30, when the balloon 3 is inflated
in the state in which the balloon 3 is disposed at the constricted portion of the
blood vessel, the hard portion 62 acts appropriately on the constricted portion of
the blood vessel.
[0075] In the balloon catheter 30, the first portion 621 of the hard portion 62 is provided
from the inside, which faces the inflatable region 33 of the balloon 3, to the outside.
Thus, even if the linear member 6 rotates with respect to the balloon 3, the linear
member 6 can orient the hard portion 62 toward the outside. Further, the hard portion
62 is disposed not only at the portion corresponding to the inflatable region 33 of
the balloon 3, but also at the portion corresponding further toward the distal end
side than the inflatable region 33. Thus, the balloon catheter 30 can cause the second
portion 622 of the hard portion 62 to act on the constricted portion of the blood
vessel further toward the distal end side than the inflatable region 33, when the
balloon 3 is inflated in the state in which the balloon 3 is disposed at the constricted
portion of the blood vessel.
[0076] In the linear member 6, the flexible portion 61 and the hard portion 62 are adjacent
in the extending direction. Thus, the linear member 6 can be easily manufactured by
connecting the respective end portions of the flexible portion 61 and the hard portion
62 in the extending direction.
Fourth embodiment
[0077] A balloon catheter 40 according to a fourth embodiment of the present invention will
be explained with reference to Fig. 12 and Fig. 13. A point in which the fourth embodiment
differs from the second embodiment is that a linear member 7 is provided in place
of the linear member 4. Hereinafter, where the configuration is the same as that of
the first embodiment to the third embodiment, the same reference numerals are assigned
and an explanation thereof is omitted.
[0078] As shown in Fig. 12, the linear member 7 includes a hard portion 71 and a flexible
portion 72. The hard portion 71 includes a first portion 711 and a second portion
712. The end portion on the proximal end side of the first portion 711 is connected
to the outer peripheral surface of the proximal end side leg portion 31 of the balloon
3, at the proximal end position M2. The second portion 712 is adjacent to the distal
end side of the first portion 711. The flexible portion 72 is adjacent to the distal
end side of the second portion 712 of the hard portion 71. The end portion on the
distal end side of the flexible portion 72 is connected to the outer peripheral surface
of the distal end side leg portion 35 of the balloon 3, at the distal end position
M1. The first portion 711 of the hard portion 71, the second portion 712 of the hard
portion 71, and the flexible portion 72 are disposed side by side in that order from
the proximal end toward the distal end along the extending direction.
[0079] The first portion 711 of the hard portion 71 corresponds to the first portion 411
(refer to Fig. 8) of the flexible portion 41 according to the first embodiment. The
second portion 712 of the hard portion 71 corresponds to the laminated portion (refer
to Fig. 8) according to the first embodiment, in which the second portion 412 of the
flexible portion 41 and the hard portion 42 are laminated. The flexible portion 72
corresponds to the third portion 413 (refer to Fig. 8) of the flexible portion 41
according to the first embodiment. The shape of each of the portions is the same.
The material of the flexible portion 72 is the same as the material of the flexible
portion 41 according to the first embodiment. The material of the hard portion 71
is the same as the material of the hard portion 42 according to the first embodiment.
[0080] Fig. 13 shows cross sections of the linear member 7 at each of a line A3 - A3, a
line B3 - B3, and a line C3 - C3. The cross-sectional shape of the first portion 711
of the hard portion 71 is a trapezoid shape. An inner portion 711A and an outer portion
711B of the first portion 711 respectively correspond to the inner portion 411A and
the outer portion 411B (refer to Fig. 8) of the flexible portion 41. A length between
the inner portion 711A and the outer portion 711B, namely, a thickness R31 of the
first portion 711, is the same as the thickness R11 in the linear member 4. The shape
of the cross section of the second portion 712 of the hard portion 71 is an equilateral
triangle shape. An inner portion 712A and an outer portion 712B of the second portion
712 respectively correspond to the inner portion 412A and the outer portion 42B (refer
to Fig. 8) of the flexible portion 41. A length between the inner portion 712A and
the outer portion 712B, namely, a thickness R32 of the second portion 712, is the
same as the thickness R12 in the linear member 4. The shape of the cross section of
the flexible portion 72 is a trapezoid shape. An inner portion 72A and an outer portion
72B of the flexible portion 72 respectively correspond to the inner portion 413A and
the outer portion 413B (refer to Fig. 8) of the flexible portion 41. A length between
the inner portion 72A and the outer portion 72B, namely, a thickness R33 of the flexible
portion 72, is the same as the thickness R13 in the linear member 4. A distal end
surface 72S and a proximal end surface 72K respectively correspond to the distal end
surface 42S and the proximal end surface 42K (refer to Fig. 8) of the hard portion
42. A first direction D31 and a second direction D32 respectively correspond to the
first direction D11 and the second direction D12 (refer to Fig. 8). A first angle
θ31 and a second angle θ32 respectively correspond to the first angle θ11 and the
second angle θ12 (refer to Fig. 8). The preferable five degrees of the first angle
θ31 is smaller than the preferable sixteen degrees of the second angle θ32.
[0081] In accordance with the inflation of the balloon 3, the second portion 712 of the
hard portion 71 of the linear member 7 tries to move away from the protruding portion
225 of the inner tube 22. At this time, the flexible portion 72 of the linear member
7 elastically deforms so as to extend along the extending direction. Thus, the second
portion 712 of the hard portion 71 easily separates from the protruding portion 225
of the inner tube 22. The outer portion 712B of the second portion 712 of the hard
portion 71 protrudes to the outside with respect to the balloon 3.
Main operations and effects of fourth embodiment
[0082] In the balloon catheter 40 according to the fourth embodiment, the second portion
712 of the hard portion 71 is disposed in a portion, of the linear member 7, that
is aligned with the position, in the extending direction, of the inflatable region
33 of the balloon 3 in the inflated state. When the balloon 3 is inflated, the flexible
portion 72 of the linear member 7 elastically deforms so as to extend along the extending
direction. In this way, the second portion 712 of the hard portion 71 moves away from
the protruding portion 225 of the inner tube 22. The outer portion 712B is disposed
on the opposite side to the inner portion 712A that faces the outer peripheral surface
of the balloon 3. Thus, with the balloon catheter 40, when the balloon 3 is inflated
in the state in which the balloon 3 is disposed at the constricted portion of the
blood vessel, the hard portion 71 acts appropriately on the constricted portion of
the blood vessel.
[0083] In the balloon catheter 40, the second portion 712 of the hard portion 71 is provided
from the inside, which faces the inflatable region 33 of the balloon 3, to the outside.
Thus, even if the linear member 7 rotates with respect to the balloon 3, the linear
member 7 can orient the hard portion 71 toward the outside. Further, the hard portion
71 is disposed not only at the portion corresponding to the inflatable region 33 of
the balloon 3, but also at the portion corresponding further toward the proximal end
side than the inflatable region 33. Thus, the balloon catheter 40 can cause the first
portion 711 of the hard portion 71 to act on the constricted portion of the blood
vessel further toward the proximal end side than the inflatable region 33, when the
balloon 3 is inflated in the state in which the balloon 3 is disposed at the constricted
portion of the blood vessel.
[0084] In the linear member 7, the hard portion 71 and the flexible portion 72 are adjacent
in the extending direction. Thus, the linear member 7 can be easily manufactured by
connecting the respective end portions of the hard portion 71 and the flexible portion
72 in the extending direction.
Fifth embodiment
[0085] A balloon catheter 50 according to a fifth embodiment of the present invention will
be explained with reference to Fig. 14 and Fig. 15. A point in which the fifth embodiment
differs from the second embodiment is that a linear member 8 is provided in place
of the linear member 4. Hereinafter, where the configuration is the same as that of
the first embodiment to the fourth embodiment, the same reference numerals are assigned
and an explanation thereof is omitted.
[0086] As shown in Fig. 14, the linear member 8 includes flexible portions 81 and 83, and
a hard portion 82. The end portion on the proximal end side of the flexible portion
81 is connected to the outer peripheral surface of the proximal end side leg portion
31 of the balloon 3, at the proximal end position M2. The hard portion 82 is adjacent
to the distal end side of the flexible portion 81. The flexible portion 83 is adjacent
to the distal end side of the hard portion 82. The end portion on the distal end side
of the flexible portion 83 is connected to the outer peripheral surface of the distal
end side leg portion 35 of the balloon 3, at the distal end position M1. The flexible
portion 81, the hard portion 82, and the flexible portion 83 are disposed side by
side in that order from the proximal end toward the distal end along the extending
direction.
[0087] The flexible portion 81 corresponds to the first portion 411 (refer to Fig. 8) of
the flexible portion 41 according to the first embodiment. The hard portion 82 corresponds
to the laminated portion (refer to Fig. 8) according to the first embodiment, in which
the second portion 412 of the flexible portion 41 and the hard portion 42 are laminated.
The flexible portion 83 corresponds to the third portion 413 (refer to Fig. 8) of
the flexible portion 41 according to the first embodiment. The shape of each of the
portions is the same. The material of the flexible portions 81 and 83 is the same
as the material of the flexible portion 41 according to the first embodiment. The
material of the hard portion 82 is the same as the material of the hard portion 42
according to the first embodiment.
[0088] Fig. 15 shows cross sections of the linear member 8 at each of a line A4 - A4, a
line B4 - B4, and a line C4 - C4. The cross-sectional shape of the flexible portion
81 is a trapezoid shape. An inner portion 81A and an outer portion 81B of the flexible
portion 81 respectively correspond to the inner portion 411A and the outer portion
411B (refer to Fig. 8) of the flexible portion 41. A length between the inner portion
81A and the outer portion 81B, namely, a thickness R41 of the flexible portion 81,
is the same as the thickness R11 in the linear member 4. The shape of the cross section
of the hard portion 82 is an equilateral triangle shape. An inner portion 82A and
an outer portion 82B of the hard portion 82 respectively correspond to the inner portion
412A and the outer portion 42B (refer to Fig. 8) of the flexible portion 41. A length
between the inner portion 82A and the outer portion 82B, namely, a thickness R42 of
the hard portion 82, is the same as the thickness R12 in the linear member 4. The
shape of the cross section of the flexible portion 83 is a trapezoid shape. An inner
portion 83A and an outer portion 83B of the flexible portion 83 respectively correspond
to the inner portion 413A and the outer portion 413B (refer to Fig. 8) of the flexible
portion 41. A length between the inner portion 83A and the outer portion 83B, namely,
a thickness R43 of the flexible portion 83, is the same as the thickness R13 in the
linear member 4. A distal end surface 82S and a proximal end surface 82K respectively
correspond to the distal end surface 42S and the proximal end surface 42K (refer to
Fig. 8) of the hard portion 42. A first direction D41 and a second direction D42 respectively
correspond to the first direction D11 and the second direction D12 (refer to Fig.
8). A first angle θ41 and a second angle θ42 respectively correspond to the first
angle θ11 and the second angle θ12 (refer to Fig. 8). The preferable five degrees
of the first angle θ41 is smaller than the preferable sixteen degrees of the second
angle θ42.
[0089] In accordance with the inflation of the balloon 3, the hard portion 82 of the linear
member 8 tries to move away from the protruding portion 225 of the inner tube 22.
At this time, the flexible portions 81 and 83 of the linear member 8 elastically deform
so as to extend along the extending direction. Thus, the hard portion 82 easily separates
from the protruding portion 225 of the inner tube 22. The outer portion 82B of the
hard portion 82 protrudes to the outside with respect to the balloon 3.
Main operations and effects of fifth embodiment
[0090] In the balloon catheter 50 according to the fifth embodiment, the hard portion 82
is disposed in a portion, of the linear member 8, that is aligned with the position,
in the extending direction, of the inflatable region 33 of the balloon 3 in the inflated
state. When the balloon 3 is inflated, the flexible portions 81 and 83 of the linear
member 8 elastically deform so as to extend along the extending direction. In this
way, the hard portion 82 moves away from the protruding portion 225 of the inner tube
22. The outer portion 82B is disposed on the opposite side to the inner portion 82A
that faces the outer peripheral surface of the balloon 3. Thus, when the balloon 3
is inflated in the state in which the balloon 3 is disposed at the constricted portion
of the blood vessel, the hard portion 82 acts appropriately on the constricted portion
of the blood vessel.
[0091] In the balloon catheter 50, the flexible portions 81 and 83 are provided on the distal
end side and the proximal end side of the hard portion 82. Thus, the linear member
8 easily extends in the extending direction when the balloon 3 is inflated. As a result,
the balloon catheter 50 can easily cause the hard portion 82 to separate from the
protruding portion 225 of the inner tube 22.
[0092] In the linear member 8, the flexible portion 81, the hard portion 82, and the flexible
portion 83 are adjacent to each other in the extending direction. Thus, the linear
member 8 can be easily manufactured by connecting the respective end portions in the
extending direction of the flexible portions 81 and 81, and the hard portion 82.
Sixth embodiment
[0093] A balloon catheter 90 according to a sixth embodiment will be explained with reference
to Fig. 16 to Fig. 19. Points in which the sixth embodiment differs from the second
embodiment are as follows:
- A linear member 9 is provided in place of the linear member 4, and
- The linear member 9 is bonded to the balloon 3 across the whole length of the linear
member 9 in the extending direction.
[0094] Hereinafter, where the configuration is the same as that of the first embodiment
to the fifth embodiment, the same reference numerals are assigned and an explanation
thereof is omitted.
Linear member 9
[0095] The linear member 9 will be explained with reference to Fig. 16 to Fig. 19. Linear
members 9A, 9B, and 9C respectively correspond to the linear members 4A, 4B, and 4C
according to the second embodiment. As shown in Fig. 16 to Fig. 18, the linear member
9 is bonded to the outer peripheral surface of the balloon 3 across the whole length
of the linear member 9 from the proximal end position M2 to the distal end position
M1. For example, the linear member 9 is bonded to the outer peripheral surface of
the balloon 3 using thermal welding. However, the linear member 9 may be bonded to
the outer peripheral surface of the balloon 3 using another method, such as adhesive
or the like. As shown in Fig 17, when the balloon 3 is in the inflated state, the
linear members 9A, 9B, and 9C extend in straight lines in the extending direction,
at positions respectively dividing the balloon 3 into three approximately equal parts
in the circumferential direction. At that time, a force in a direction to try and
elongate the linear member 9 in the extending direction (hereinafter referred to as
a "force in an elongation direction") acts on the linear member 9. In contrast to
this, when the balloon 3 is in the deflated state, the force in the elongation direction
does not act on the linear member 9.
[0096] As shown in Fig. 16 and Fig. 18, the linear member 9 includes a flexible portion
91 and a hard portion 92. The flexible portion 91 extends between the proximal end
position M2 and the distal end position M1. The flexible portion 91 includes a first
portion 911, a second portion 912, and a third portion 913. The first portion 911,
the second portion 912, and the third portion 913 respectively correspond to sections
of the flexible portion 91 that is divided into three in the extending direction.
The first portion 911 is bonded to the outer peripheral surfaces of the proximal end
side leg portion 31 and the proximal end side cone region 32 of the balloon 3. The
second portion 912 is adjacent to the distal end side of the first portion 911. The
second portion 912 is bonded to the outer peripheral surface of the inflatable region
33 of the balloon 3. The third portion 913 is adjacent to the distal end side of the
second portion 912. The third portion 913 is bonded to the outer peripheral surfaces
of the distal end side cone region 34 and the distal end side leg portion 35 of the
balloon 3. The hard portion 92 is laminated to a portion, of the second portion 912
of the flexible portion 91, on the opposite side to the portion bonded to the balloon
3.
[0097] Fig. 19 shows cross sections of the linear member 9 at each of a line A5 - A5, a
line B5 - B5, and a line C5 - C5 in a state in which the force in the elongation direction
is not acting on the linear member 9. The cross-sectional shape of the linear member
9 is a trapezoid shape or an equilateral triangle shape. Specifically, it is as described
below.
[0098] The shape of the cross section of the flexible portion 91 (the first portion 911
to the third portion 913) is the trapezoid shape. Hereinafter, of the first portion
911 of the flexible portion 91, a portion bonded to the balloon 3 (refer to Fig. 16)
is referred to as an "inner portion 911A." Of the first portion 911, a portion on
the opposite side to the inner portion 911A is referred to as an "outer portion 911B."
Of the second portion 912 of the flexible portion 91, a portion bonded to the balloon
3 is referred to as an "inner portion 912A." Of the second portion 912, a portion
on the opposite side to the inner portion 912A is referred to as a "boundary 912B."
Of the third portion 913 of the flexible portion 91, a portion bonded to the balloon
3 is referred to as an "inner portion 913A." Of the third portion 913, a portion on
the opposite side to the inner portion 913A is referred to as an "outer portion 913B."
The inner portions 911A, 912A, and 913A respectively correspond to the lower base
of the trapezoid that is the cross-sectional shape. The outer portions 911B and 913B,
and the boundary 912B respectively correspond to the upper base of the trapezoid that
is the cross-sectional shape.
[0099] The shape of the cross section of the hard portion 92 is an equilateral triangle
shape having the boundary 912B of the second portion 912 as one side. The hard portion
92 protrudes to the outside from the boundary 912B of the second portion 912 of the
flexible portion 91. Hereinafter, an end portion on the outside of the hard portion
42 is referred to as an "outer portion 92B." The outer portion 92B corresponds to
an apex of the equilateral triangle shape, and thus is peaked.
[0100] A length between the inner portion 911A and the outer portion 911B of the first portion
911, namely, a thickness of a portion of the flexible portion 91 further toward the
proximal end side than the hard portion 92, is denoted as a thickness R51. A length
between the inner portion 912A and the boundary 912B of the second portion 912, namely,
a thickness of a portion of the flexible portion 91 that overlaps with the hard portion
92 in the radial direction, is denoted as R52. A length between the inner portion
913A and the outer portion 913B of the third portion 913, namely, a thickness of a
portion of the flexible portion 91 further toward the distal end side than the hard
portion 92, is denoted as R53. In this case, the thicknesses R51, R52, and R53 are
equal.
[0101] An end surface on the distal end side of the hard portion 92 is referred to a "distal
end surface 92S." A virtual first direction D51 is defined that extends toward the
outside along the distal end surface 92S of the hard portion 92. The first direction
D51 is inclined toward the proximal end side with respect to the direction orthogonal
to the extending direction. An end surface on the proximal end side of the hard portion
92 is referred to as a "proximal end surface 92K." A virtual second direction D52
is defined that extends toward the outside along the proximal end surface 92K of the
hard portion 92. The second direction D52 is inclined toward the distal end side with
respect to the direction orthogonal to the extending direction. An acute angle, of
angles formed between the first direction D51 and the extending direction, is defined
as a first angle θ51. The first angle θ51 is an angle between 4 to 13 degrees, for
example. The first angle θ51 is preferably 5 degrees. An acute angle, of angles formed
between the second direction D52 and the extending direction is defined as a second
angle θ52. The second angle θ52 is an angle between 5 to 16 degrees, for example.
The second angle θ52 is preferably 16 degrees. The preferable five degrees of the
first angle θ51 is smaller than the preferable sixteen degrees of the second angle
θ52.
[0102] As shown in Fig. 18, a position of a boundary on the distal end side of the second
portion 912 of the flexible portion 91, in other words, a position of a boundary between
the second portion 912 and the third portion 913, is aligned, in the extending direction,
with the position P11 of the end portion on the distal end side of the marker 22A.
A position of a boundary on the proximal end side of the second portion 912 of the
flexible portion 91, in other words, a position of a boundary between the first portion
911 and the second portion 912, is aligned, in the extending direction, with the position
P21 of the end portion on the proximal end side of the marker 22B. Note that the hard
portion 92 of the linear member 9 is laminated on the second portion 912 of the flexible
portion 91. Thus, the inflatable region 33 of the balloon 3, the second portion 912
of the flexible portion 91, and the hard portion 92 are all disposed in the same position
in the extending direction.
[0103] As shown in Fig. 19, two notches 51, which extend toward the inside in the radial
direction from the outer portion 92B of the hard portion 92, are formed in the linear
member 9. Each of the two notches 51 is formed by cutting out a part of the linear
member 9. A cross-sectional shape of each of the notches 51 is a wedge shape. The
two notches 51 are disposed side by side at an equal interval in the extending direction.
[0104] Each of the notches 51 includes surfaces 51A and 51B that face each other in the
extending direction. When the balloon 3 is not in the inflated state, namely, in the
state in which the force in the elongation direction is not acting on the linear member
9, a direction that extends to the outside along the surface 51A is inclined toward
the proximal end side with respect to the direction orthogonal to the extending direction.
A direction that extends to the outside along the surface 51B is inclined toward the
distal end side with respect to the direction orthogonal to the extending direction.
The surfaces 51A and 51B are disposed with an interval therebetween in the extending
direction. A gap is formed between the surfaces 51A and 51B. The surfaces 51A and
51B are connected by respective inside end portions thereof. The end portions that
connect the surfaces 51A and 51B are, in other words, an end portion (hereinafter
referred to as a "bottom portion") 51C of the inside of the notch 51. The bottom portion
51C is positioned further to the inside, in the radial direction, than the boundary
912B that represents the boundary between the second portion 912 of the flexible portion
91 and the hard portion 92.
[0105] When the balloon 3 inflates as a result of the compressed fluid being supplied from
the hub 5, the force in the elongation direction acts on the first portion 911 and
the third portion 913 of the flexible portion 91 of the linear member 9. As a result,
the first portion 911 and the third portion 913 elastically deform so as to extend
along the extending direction. Further, of the linear member 9, the force in the extending
direction also acts on the section at which the second portion 912 of the flexible
portion 91 and the hard portion 92 are laminated. Here, in comparison to the flexible
portion 91, the hard portion 92 does not easily extend. As a result of the second
portion 912 of the flexible portion 91 elastically deforming due to the force in the
extending direction, the respective surfaces 51A and 51B of the plurality of notches
51 separate from each other in the extending direction. As a result, the elastic deformation
of the second portion 912 of the flexible portion 91 is not easily suppressed by the
hard portion 92. Thus, of the linear member 9, even the section in which the second
portion 912 of the flexible portion 91 and the hard portion 92 are laminated elastically
deforms so as to extend in the extending direction in accordance with the inflation
of the balloon 3. As a result of the above, the linear member 9 follows the inflation
of the balloon 3 and extends in the extending direction across the whole length of
the linear member 9 in the extending direction.
[0106] Meanwhile, when the balloon 3 deflates as a result of the compressed fluid being
discharged from the balloon 3 in the inflated state, the flexible portion 91 of the
linear member 9 that is extended in the extending direction contracts due to a restoring
force. The surfaces 51A and 51B of the notches 51 of the hard portion 92 of the linear
member 9 approach each other with a space therebetween in the extending direction.
The linear member 9A is covered from the outside by the pleat 3A, the linear member
9B is covered from the outside by the pleat 3B, and the linear member 9C is covered
from the outside by the pleat 3C.
Main operations and effects of sixth embodiment
[0107] In the balloon catheter 90, when the balloon 3 is inflated, the force that tries
to elongate acts on the linear member 9. If the linear member 9 does not extend well
even when this force is acting, the linear member 9 cannot follow the inflation of
the balloon 3 and there is a possibility that the linear member 9 may break away from
the balloon 3. Further, there is a case in which the inflation of the balloon 3 is
obstructed by the linear member 9. Thus, it is preferable that the extendability of
the linear member 9 be high. On the other hand, in order to cause the linear member
9 to act appropriately on the blood vessel when the balloon 3 is inflated, it is preferable
that the hardness of the linear member 9 be harder.
[0108] In response to this, in the balloon catheter 90, when the balloon 3 is inflated,
the outer portion 92B of the hard portion 92 of the linear member 9 protrudes to the
outside with respect to the balloon 3. The hardness of the hard portion 92 is harder
than the flexible portion 91. Thus, the linear member 9 can cause the hard portion
92 to act appropriately on the blood vessel when the balloon 3 is inflated. For example,
since the outer portion 92B of the hard portion 92 is peaked, the hard portion 92
easily bites into the lesioned part (not shown in the drawings) of the blood vessel.
As a result, in a state in which the linear member 9 causes the balloon 3 to be in
a state of not easily slipping with respect to the lesioned part of the blood vessel,
the lesioned part can be expanded from inside by the inflation of the balloon 3.
[0109] The flexible portion 91 of the linear member 9 can extend. Thus, when the linear
member 9 tries to extend in accordance with the inflation of the balloon 3, the first
portion 911 and the third portion 913, of the flexible portion 91, on which the hard
portion 92 is not laminated extend in a favorable manner, and follow the balloon 3.
Further, the two notches 51 are formed in the linear member 9. Thus, when the second
portion 912 of the flexible portion 91 tries to extend in accordance with the inflation
of the balloon 3, the surfaces 51A and 51B of each of the notches 51 separate from
each other, thus suppressing the hard portion 92 from obstructing the extending of
the second portion 912 of the flexible portion 91. As a result, the linear member
9 can extend appropriately across the whole length of the linear member 9 in accordance
with the inflation of the balloon 3, and can follow the inflation of the balloon 3.
Thus, the balloon catheter 90 can inhibit the linear member 9 from breaking away from
the balloon 3 when the balloon 3 is inflated, or inhibit the linear member 9 from
obstructing the inflation of the balloon 3.
[0110] The bottom portion 51C of each of the notches 51 is positioned further to the inside,
in the radial direction, than the boundary 912B between the second portion 912 of
the flexible portion 91 and the hard portion 92. In this case, the hard portion 92
is divided into three by the two notches 51. Thus, the linear member 9 can appropriately
suppress the hard portion 92 from obstructing the extending of the second portion
912 of the flexible portion 91. As a result, the balloon catheter 90 can even more
appropriately inhibit the linear member 9 from breaking away from the balloon 3 when
the balloon 3 is inflated, or inhibit the linear member 9 from obstructing the inflation
of the balloon 3.
[0111] The surfaces 51A and 51B of each of the two notches 51 are disposed so as to be separated
from each other in the extending direction. In this case, the linear member 9 can
easily bend in the direction orthogonal to the extending direction at the section
in which the notches 51 are formed. As a result, when the balloon 3 bends in the direction
orthogonal to the extending direction, the balloon catheter 90 can cause the linear
member 9 to follow the balloon 3 and bend. Thus, the balloon catheter 90 can suppress
the linear member 9 from breaking away from the balloon 3 when the balloon 3 bends.
[0112] The linear member 9 is bonded to the outer peripheral surface of the balloon 3 between
the distal end position M1 and the proximal end position M2. As a result, the linear
member 9 is held in a fixed position with respect to the balloon 3. Thus, the balloon
catheter 90 can cause the linear member 9 to act on the blood vessel when the balloon
3 is inflated, while the linear member 9 is held in a correct position with respect
to the balloon 3. Further, by directly bonding the linear member 9 to the balloon
3, the balloon catheter 90 can inhibit the position of the linear member 9 with respect
to the balloon 3 from changing in accordance with the inflation of the balloon 3.
[0113] The first direction D51, which extends to the outside along the distal end surface
92S that is the end portion of the hard portion 92 on the distal end side, is inclined
toward the proximal end side. In this case, when the balloon catheter 90 moves inside
the blood vessel in the course of the user causing the balloon 3 to approach the constricted
portion of the blood vessel, the linear member 9 can be inhibited from catching on
the inner wall of the blood vessel. Thus, the user can smoothly move the balloon 3
as far as the constricted portion of the blood vessel. Further, the second direction
D52, which extends to the outside along the proximal end surface 92K that is the end
portion of the hard portion 92 on the proximal end side, is inclined toward the distal
end side. In this case, when the balloon catheter 90 moves inside the blood vessel
in the course of the user pulling the balloon catheter 90 out from the blood vessel,
the linear member 9 can be inhibited from catching on the inner wall of the blood
vessel. Thus, the user can easily pull the balloon catheter 90 out from the blood
vessel.
[0114] The linear member 9 is formed of a synthetic resin. In this case, the linear member
9 that includes the flexible portion 91 and the hard portion 92 can be easily manufactured
by injection molding, extrusion molding or the like.
Seventh embodiment and eighth embodiment
[0115] A seventh embodiment and an eighth embodiment will be explained with reference to
Fig. 20 and Fig. 21. In the seventh embodiment, in place of the notches 51 of the
sixth embodiment, notches 52 (refer to Fig. 20) are formed in the linear member 9.
In the eighth embodiment, in place of the notches 51 of the sixth embodiment, notches
53 (refer to Fig. 21) are formed in the linear member 9. Other parts of the configuration
are the same as those of the sixth embodiment. Hereinafter, where the configuration
is the same as that of the above-described embodiments, the same reference numerals
are assigned and an explanation thereof is omitted.
[0116] As shown in Fig. 20, in the seventh embodiment, the notch 52 includes surfaces 52A
and 52B. The end portion on the inside of the notch 52 is referred to as a "bottom
portion 52C." The surfaces 52A and 52B, and the bottom portion 52C respectively correspond
to the surfaces 51A and 51B, and the bottom portion 51C of the notch 51 of the sixth
embodiment. In the notch 52, a position of the bottom portion 52C in the radial direction
is different to that of the notch 51. In the notch 52, the bottom portion 52C is positioned
in substantially the same position as the boundary 912B between the second portion
912 of the flexible portion 91 and the hard portion 92. In this case, similarly to
the sixth embodiment, the hard portion 92 is divided into three in the extending direction
by two of the notches 52. As a result, the linear member 9 can appropriately suppress
the extending of the second portion 912 of the flexible portion 91 from being obstructed
by the hard portion 92. Thus, similarly to the sixth embodiment, the balloon catheter
90 can even more appropriately inhibit the linear member 9 from breaking away from
the balloon 3 when the balloon 3 is inflated, or inhibit the linear member 9 from
obstructing the inflation of the balloon 3. In addition, in contrast to the sixth
embodiment, a part of the notch 52 is not formed in the flexible portion 91. Therefore,
in comparison to the case in which the part of the notch 51 is formed in the second
portion 912 of the flexible portion 91 as in the sixth embodiment, the strength of
the second portion 912 of the flexible portion 91 is maintained when extending.
[0117] As shown in Fig. 21, in the eighth embodiment, the notch 53 includes surfaces 53A
and 53B. The end portion on the inside of the notch 53 is referred to as a "bottom
portion 53C." The surfaces 53A and 53B, and the bottom portion 53C respectively correspond
to the surfaces 51A and 51B, and the bottom portion 51C of the notch 51 of the above-described
embodiment. In the notch 53, a position of the bottom portion 53C in the radial direction
is different to that of the notches 51 and 52. In the notch 53, the bottom portion
53C is positioned further to the outside than the boundary 912B between the second
portion 912 of the flexible portion 91 and the hard portion 92.
[0118] When the notch 53 is formed in the linear member 9, in contrast to the sixth embodiment
and the seventh embodiment, the hard portion 92 is not divided in the extending direction
by the notch 53. However, of the hard portion 92, a portion further to the inside
than the bottom portion 53C of the notch 53 extends easily in the extending direction,
compared to a portion in which the notch 53 is not formed. Therefore, of the linear
member 9, the portion in which the second portion 912 of the flexible portion 91 and
the hard portion 92 are laminated extends in the extending direction in accordance
with the inflation of the balloon 3. Thus, similarly to the sixth embodiment and the
seventh embodiment, the balloon catheter 90 can inhibit the linear member 9 from breaking
away from the balloon 3 when the balloon 3 is inflated, or inhibit the linear member
9 from obstructing the inflation of the balloon 3.
[0119] The depth of the notch 53 is smaller than that of the notches 51 and 52, and therefore,
the space between the surfaces 53A and 53B can be minimized when the surfaces 53A
and 53B separate from each other in accordance with the inflation of the balloon 3.
As a result, an area of the outer portion 92B of the hard portion 92 can be made larger
than in the case of the sixth embodiment and the seventh embodiment. Note that, when
the balloon 3 is inflated, the outer portion 92B of the hard portion 92 comes into
contact with the blood vessel wall. Thus, since the balloon catheter 90 can increase
the area of the portion (the outer portion 92B of the hard portion 92) of the linear
member 9 that comes into contact with the blood vessel wall, the balloon catheter
90 can cause the linear member 9 to act appropriately on the blood vessel when the
balloon 3 is inflated.
Ninth embodiment
[0120] A ninth embodiment will be explained with reference to Fig. 22. In the ninth embodiment,
incisions 54 are formed in place of the notches 51 of the sixth embodiment. Other
parts of the configuration are the same as those of the sixth to eighth embodiments.
Hereinafter, where the configuration is the same as that of the above-described embodiments,
the same reference numerals are assigned and an explanation thereof is omitted.
[0121] As shown in Fig. 22, the incision 54 extends to the inside along the radial direction,
from the outer portion 92B of the hard portion 92. The incision 54 includes surfaces
54A and 54B that face each other in the extending direction. An end portion (hereinafter
referred to as a "bottom portion") 54C on the inside of each of the incisions 54 is
positioned further to the inside, in the radial direction, than the boundary 912B
between the second portion 912 of the flexible portion 91 and the hard portion 92.
[0122] When the compressed fluid is not supplied from the hub 5 and the balloon 3 is not
in the inflated state, the force in the elongation direction does not act on the linear
member 9. In this case, as shown in Fig. 22, the surfaces 54A and 54B are in contact
with each other. A gap is not formed between the surfaces 54A and 54B. On the other
hand, when the balloon 3 is inflated as a result of the compressed fluid being supplied
from the hub 5, the force in the elongation direction acts on the portion, of the
linear member 9, at which the second portion 912 of the flexible portion 91 and the
hard portion 92 are laminated. The surfaces 54A and 54B of the incision 54 separate
from each other in the extending direction, as a result of the elastic deformation
of the second portion 912 of the flexible portion 91. The hard portion 92 is divided
in the extending direction by the incisions 54. Thus, the elastic deformation of the
second portion 912 of the flexible portion 91 is not easily suppressed by the hard
portion 92. As a result, the portion of the linear member 9 at which the second portion
912 of the flexible portion 91 and the hard portion 92 are laminated extends in the
extending direction in accordance with the inflation of the balloon 3. Meanwhile,
when the balloon 3 is deflated as a result of the compressed fluid being discharged
from the balloon 3 in the inflated state, the flexible portion 91 of the linear member
9 that is extended in the extending direction contracts due to the restoring force.
The surfaces 54A and 54B of the incision 54 of the hard portion 92 once more come
into contact with each other. The surfaces 54A and 54B return to the state in which
the gap is not formed therebetween.
Main operations and effects of ninth embodiment
[0123] As described above, in the ninth embodiment, the surfaces 54A and 54B of the incision
54 are in contact with each other when the balloon 3 is not inflated and the gap between
them is not formed. In this case, even when the surfaces 54A and 54B separate from
each other as a result of the inflation of the balloon 3, the gap between the surfaces
54A and 54B can be suppressed to a minimum. Thus, the area of the outer portion 92B
of the hard portion 92 of the linear member 9 can be made as large as possible. As
a result, since the balloon catheter 90 can make the area of the portion (the outer
portion 92B of the hard portion 92) of the linear member 9 that comes into contact
with the blood vessel wall as large as possible, the balloon catheter 90 can cause
the linear member 9 to act even more appropriately on the blood vessel when the balloon
3 is inflated.
[0124] It should be noted that, in the ninth embodiment, similarly to the case of the notch
52 (refer to Fig. 20) of the seventh embodiment, the bottom portion 54C may be positioned
in substantially the same position as the boundary 912B between the second portion
912 of the flexible portion 91 and the hard portion 92. Further, in the ninth embodiment,
similarly to the case of the notch 53 (refer to Fig. 21) of the eighth embodiment,
the bottom portion 54C may be positioned further to the outside than the boundary
912B between the second portion 912 of the flexible portion 91 and the hard portion
92.
[0125] The notch 51 of the sixth embodiment, the notch 52 of the seventh embodiment, the
notch 53 of the eighth embodiment, and the incision 54 of the ninth embodiment may
also be formed in the linear members 4, 6, 7, and 8 of the balloon catheters 10, 20,
40, and 50 according to the first to fifth embodiments.
[0126] For example, a state of the linear member 4 will be explained when the balloon 3
inflates as a result of the compressed fluid being supplied from the hub 5, in a case
in which a plurality of the notches 51 are formed in the linear member 4 of the balloon
catheter 10 according to the first embodiment. In accordance with the inflation of
the balloon 3, the hard portion 42 of the linear member 4 tries to move away from
the protruding portion 225 of the inner tube 22. At this time, the force in the elongation
direction acts on the first portion 411 and the third portion 413 of the flexible
portion 41 of the linear member 4. As a result, the first portion 411 and the third
portion 413 elastically deform so as to extend in the extending direction. Thus, the
hard portion 42 separates easily from the protruding portion 225 of the inner tube
22. Further, the force in the extending direction also acts on the section of the
linear member 4 at which the second portion 412 of the flexible portion 41 and the
hard portion 42 are laminated. Here, the respective surfaces 51A and 51B of the plurality
of notches 51 of the flexible portion 41 separate from each other in the extending
direction in accordance with the elastic deformation of the second portion 412 of
the flexible portion 41 caused by the force in the extending direction. As a result,
the elastic deformation of the second portion 412 of the flexible portion 41 is not
easily suppressed by the hard portion 42. Therefore, the section of the linear member
4 at which the second portion 412 of the flexible portion 41 and the hard portion
42 are laminated also elastically deforms so as to extend in the extending direction
in accordance with the inflation of the balloon 3. As a result of the above, the linear
member 4 extends in the extending direction over the whole length of the linear member
4 in the extending direction.
[0127] Meanwhile, when the balloon 3 deflates as a result of the compressed fluid being
discharged from the balloon 3 in the inflated state, the flexible portion 41 of the
linear member 4 that is extended in the extending direction contracts due to the restoring
force. The surfaces 51A and 51B of the notches 51 of the hard portion 42 of the linear
member 4 approach each other with the space therebetween in the extending direction.
The hard portion 42 of the linear member 4 moves closer to the protruding portion
225 of the inner tube 22. The warping of the linear member 4 is suppressed by the
linear member 4 contracting.
[0128] As described above, when the notches 51 are formed in the linear member 4 of the
balloon catheter 10, the linear member 4 can be caused to appropriately extend over
the whole length of the linear member 4 in accordance with the inflation of the balloon
3. As a result, the balloon catheter 10 can inhibit the linear member 4 from breaking
away from the balloon 3 when the balloon 3 is inflated, or inhibit the linear member
4 from obstructing the inflation of the balloon 3. Further, in the case of the balloon
catheter 10, the end portion on the distal end side of the linear member 4 is connected
to the balloon 3, and the end portion on the proximal end side of the linear member
4 is connected to the catheter shaft 2 via the mounting member 21A. Other portions
of the linear member 4 are not bonded to the balloon 3. Further, when the linear member
4 is bonded to the catheter shaft 2, a manufacturing process is easier than when the
linear member 4 is bonded to the balloon 3. Thus, the manufacturing of the balloon
catheter 10 can be simplified.
[0129] In the above description, a part of the portion of the linear member 4 excepting
both the end portions on the distal end side and the proximal end side may be bonded
to the balloon 3. For example, the second portion 412 of the flexible portion 41 of
the linear member 4 may be bonded to the inflatable region 33 of the balloon 3.
Modified examples
[0130] The present invention is not limited to the above-described embodiments and various
modifications are possible. The number of the linear members 4, 6, 7, 8, and 9 is
not limited to three, and may be another quantity. The linear members 4, 6, 7, 8,
and 9 are members that extend in a substantially straight line along the extending
direction. In contrast, the linear members 4, 6, 7, 8, and 9 may be members that extend
in a spiral shape along the extending direction. The hard portions 42 and 92 may be
provided across the whole length of the flexible portions 41 and 91 in the extending
direction.
[0131] The outer portions of the hard portions 42, 62 (the first portion 621), 71 (the second
portion 712), 82, and 92, which are each disposed in a position corresponding to the
inflatable region 33 of the balloon 3, correspond to the equilateral triangle shape
and are peaked. The outer portions of the hard portions 42, 62, 71, 82, and 92 have
the function of suppressing the slipping of the balloon 3. The shape of the outer
portions of the hard portions 42, 62, 71, 82, and 92 is not limited to that of the
above-described embodiments. For example, an angle of the outer portions of the hard
portions 42, 62, 71, 82, and 92 may be steep. In this case, the outer portions of
the hard portions 42, 62, 71, 82, and 92 may function, for example, as a cutting blade
for cutting open the lesioned part when the balloon 3 is in the inflated state.
[0132] The cross-sectional shape of the linear members 4, 6, 7, 8, and 9 is not limited
to the above-described examples. For example, the cross-sectional shape of the hard
portions 42, 62, 71, 82, and 92 may be an isosceles triangle shape or a triangle shape
having three sides of mutually differing lengths. In the first embodiment, the cross-sectional
shape of the flexible portion 41 may be a semi-circle that is cut out from the outside,
or may be a polygonal shape. The cross-sectional shape including the flexible portion
41 and the hard portion 42 may be a circular shape, or may be a polygonal shape. Note
that this also applies to the second to ninth embodiments.
[0133] In the above-described embodiments, the end portions on the distal end side of the
linear members 4, 6, 7, 8, and 9 are connected to the distal end side leg portion
35, at the distal end position M1. In contrast to this, the end portions on the distal
end side of the linear members 4, 6, 7, 8, and 9 may be connected to the inner tube
22. The end portion on the proximal end side of the linear member 4 is connected to
the mounting member 21A. The end portions on the proximal end side of the linear members
6, 7, 8, and 9 are connected to the proximal end side leg portion 31. In contrast
to this, the end portions on the proximal end side of the linear members 4, 6, 7,
8, and 9 may be connected to the outer tube 21.
[0134] The end portion on the proximal end side of the linear member 4 need not necessarily
be able to move along the extending direction. Specifically, for example, the end
portion on the proximal end side of the linear member 4 may be connected to the outer
peripheral surface of the outer tube 21, further toward the proximal end side than
the portion, of the outer tube 21, at which the proximal end side leg portion 31 of
the balloon 3 is connected.
[0135] Each of the first directions D11, D21, D31, D41, and D51 is inclined toward the proximal
end side with respect to the direction orthogonal to the extending direction. Each
of the second directions D12, D22, D32, D42, and D52 is inclined toward the distal
end side with respect to the direction orthogonal to the extending direction. In contrast
to this, the first directions D11, D21, D31, D41, and D51 and the second directions
D12, D22, D32, D42, and D52 may extend in the direction orthogonal to the extending
direction. The preferable five degrees of each of the first angles θ11, θ21, θ31,
θ41, and θ51 is smaller than the preferable sixteen degrees of each of the second
angles θ12, θ22, θ32, θ42, and θ52. In contrast to this, a preferable value of each
of the first angles θ11, θ21, θ31, θ41, and θ51 may be the same as a preferable value
of each of the second angles θ12, θ22, θ32, θ42, and θ52. Further, the preferable
value of each of the first angles θ11, θ21, θ31, θ41, and θ51 may be larger than the
preferable value of each of the second angles θ12, θ22, θ32, θ42, and θ52.
[0136] The proximal end side thicknesses R11, R21, R31, and R41 are larger than the distal
end side thicknesses R13, R23, R33, and R43. In contrast to this, the proximal end
side thicknesses R11, R21, R31, and R41 may be the same as the distal end side thicknesses
R13, R23, R33, and R43. The proximal end side thicknesses R11, R21, R31, and R41 may
be smaller than the distal end side thicknesses R13, R23, R33, and R43. The proximal
end side thickness R51 may be larger or smaller than the distal end side thickness
R53.
[0137] The position of the boundary on the distal end side of the inflatable region 33 is
aligned, in the extending direction, with the position P11 of the end portion on the
distal end side of the marker 22A. The position of the boundary on the proximal end
side of the inflatable region 33 is aligned, in the extending direction, with the
position P21 of the end portion on the proximal end side of the marker 22B. However,
the position of the boundary on the distal end side of the inflatable region 33 need
not necessarily be completely aligned, in the extending direction, with the position
P11 on the distal end side of the marker 22A. For example, the position of the boundary
on the distal end side of the inflatable region 33 may be aligned, in the extending
direction, with any position between the position P11 of the end portion on the distal
end side of the marker 22A and a position P12 of the end portion on the proximal end
side of the marker 22A. The position of the boundary on the proximal end side of the
inflatable region 33 need not necessarily be completely aligned, in the extending
direction, with the position P21 on the proximal end side of the marker 22B. For example,
the position of the boundary on the proximal end side of the inflatable region 33
may be aligned, in the extending direction, with any position between the position
P21 of the end portion on the proximal end side of the marker 22B and a position P22
of the end portion on the distal end side of the marker 22B. In other words, it is
sufficient that the positions of the marker 22A and the marker 22B respectively correspond
to the position of the boundary on the distal end side of the inflatable region 33
and the position of the boundary on the proximal end side of the inflatable region
33. Further, the number of the markers is not limited to two, and may be three or
more.
[0138] Each of the boundary portion between the proximal end side cone region 32 and the
inflatable region 33 and the boundary portion between the inflatable region 33 and
the distal end side cone region 34 of the balloon 3 in the inflated state may be curved.
In this case, for example, with respect to the positions of each of the boundaries,
when a plurality of virtual planes that touch the respectively curved boundary portions
are defined, positions of the boundary portions that touch the virtual plane, of the
plurality of virtual planes, that forms an acute angle of 45 degrees with the extending
direction may be the positions of each of the boundaries. Further, in the above-described
embodiments, each of the proximal end side cone region 32 and the distal end side
cone region 34 is a region whose diameter changes linearly from the proximal end side
toward the distal end side. However, each of the proximal end side cone region 32
and the distal end side cone region 34 may be a region whose diameter changes in a
curved manner from the proximal end side toward the distal end side. In addition,
one of the proximal end side cone region 32 and the distal end side cone region 34
may be the region whose diameter changes in the curved manner and the other may be
the region whose diameter changes linearly.
[0139] The distal end surfaces 42S, 62S, 72S, 82S, and 92S, and the proximal end surfaces
42K, 62K, 72K, 82K, and 92K of the linear members 4, 6, 7, 8, and 9 need not necessarily
have a straight line shape. For example, at least either of the distal end surfaces
42S, 62S, 72S, 82S, and 92S, or the proximal end surfaces 42K, 62K, 72K, 82K, and
92K may have level differences.
[0140] The outer portions 412B and 912B have a straight line shape. The outer portions 412B
and 912B may have a curved shape. In other words, for example, the hard portions 42
and 92 may have a circular arc-shaped cross section.
[0141] The present invention can be applied to a device other than the balloon catheter
that includes the balloon 3 that is inflated by the supply of the compressed fluid.
For example, the linear members 4, 6, 7, 8, and 9 may be applied to a device that
has a mechanically expanding mechanism in place of the balloon 3. In the above-described
embodiments, the example is given of the catheter shaft 2 that has the outer tube
21 and the inner tube 22. In the present invention, the catheter shaft 2 need not
necessarily have the outer tube 21 and the inner tube 22. For example, the catheter
shaft 2 may have only one flexible tube.
[0142] In the sixth to ninth embodiments, the positions in the radial direction of the bottom
portions 51C to 53C of each of the notches 51 to 53, and the bottom portions 54C of
the incisions 54 may be positions that are substantially the same position as the
inner portion 912A of the second portion 912 of the flexible portion 91. In other
words, the linear member 9 may be divided in the extending direction by the notches
51 to 53 or the incisions 54.
[0143] In the sixth to eighth embodiments, the cross-sectional shape of the notches 51 to
53 is not limited to the wedge shape. For example, a notch may be a slit whose cross-sectional
shape is a semi-circular shape, a rectangular shape, a trapezoid shape or the like,
or may be a slit whose outside end portions are rounded. Further, a plurality of slits
having mutually different cross-sectional shapes may be formed in the linear member
9. When the notch has the semi-circular shape, the rectangular shape, the trapezoid
shape or the like, the position of a bottom portion thereof may be further to the
inside or to the outside, in the radial direction, than the boundary 912B between
the second portion 912 of the flexible portion 91 and the hard portion 92. In addition,
the position of the bottom portion may be a position that is substantially the same
position as the boundary 912B in the radial direction. The number of the notches 51
to 53 formed in the linear member 9 is not limited to two, and may be another quantity,
such as one or more, for example.
[0144] In the ninth embodiment, the incision 54 may extend in a direction intersecting with
the radial direction, to the inside from the outer portion 92B of the hard portion
92. The shape of the incision 54 is not limited to the straight line and may be a
curved line. The incision may be a slit whose outside end portions are rounded. Further,
a plurality of slits including the notches and the incisions having mutually different
shapes may be formed in the linear member 9.
[0145] In the sixth to ninth embodiments, the linear member 9 may be bonded to the balloon
3 only in the vicinity of each of the distal end position M1 and the proximal end
position M2. Of the linear member 9, a section excluding the vicinity of each of the
distal end position M1 and the proximal end position M2 need not necessarily be bonded
to the balloon 3. The end portion on the distal end side of the linear member 9 may
be connected to the inner tube 22. The end portion on the proximal end side of the
linear member 9 may be connected to the outer tube 21.
[0146] In the sixth to ninth embodiments, the flexible portion 91 of the linear member 9
includes the first portion 911, the second portion 912, and the third portion 913.
However, the flexible portion 91 need not necessarily include the first portion 911
and the third portion 913. For example, the linear member 9 may be configured by the
hard portion 92 and the second portion 912. In this case, the second portion 912 is
bonded with the outer peripheral surface of the inflatable region 33 of the balloon
3 using adhesive or the like. In addition, the flexible portion 91 of the linear member
9 may be configured by the second portion 912 and one of the first portion 911 and
the third portion 913.